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March 23 1926. R 16,295

. S. G. DOWN FLUID PRESSURE BRAKE Original Filed Dec.. 27 1921 myENToRSIEENEY G. DOWN ATTORNEY Reiss'ued Mar. 23, 1926.

- UNITED STATES- i 11,16,295 PATENT OFFICE.

SiIIDNEY G. DOWN, OF PITTSBURGH, PENNSYLVANIA, QASSIGNOR TO THE WESTING-HOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORA- TION orPENNSYLVANIA.

Original No. 1,488,479, dated April 1, 1924, Serial No. 524,926, filedDecember 2'7, 1921. Application for FLUID-PRESSURE BRAKE.

reissue filed November 6, 1925. Serial'No. 67,464.

This invention relates to fluid pressure brakes, and more particularlyto, the locomotive brake equipment,

With the usual standard locomotive brake equipment, the brake valvedevice is provided with a full release position, in which fluid underpressure is supplied directly from the main reservoirto the brake pipe,and a running position, inuwhich fluid is supplied from'the mainreservoir through a feed valve device to the brake pipe, at a I limitedrate and at the pressure. normally to be maintained in the brake pipe.

In operation, the brake valve handle is normally left in runningposition while the brakes remain released and it has been found that insome instances, when the brake pipe pressure is reduced byleakage,-..the

feed valve device will sometimes fail to supply fluid'to the brake pipeto compensate for the leakage at a rate sufficient to prevent movementof one or more'triples to application position. i l I One object of myinvention is to provide alocomotive brake equipment having means forobviating the above ditlicult y.v

,With the usual standard locomotive brake equipment, where. the feedvalve device is placed between the main reservoir volume and the brakevalve device, the engineer, in releasing the brakes, must manipulate thebrake valve handle between release and running positions, and undercertain conditions of train lengths and brake operation he is calledupon to move the brake valve handle several times between running andrelease positions, to release such brakes as may have applied, due tothe rapid fall of pressure in the brake pipe as occasioned by leakagefrom the brake pipe and also by the equalization of pressure from thehead to the rear end of long trains.

Another object of my invention is to simplify the operation of releasingthe brakes by providing a locomotive brake equipment in which therelease of the brakes may be satisfactorily controlled by the-movementof the brake .valve handle to one position instead of two.

It has been proposed to provide a locomotive brake equipment wherein nofeed valve device-is employed but in which the release of the brakes-iscontrolled by the movement of the brake valve handle to one positioninstead of two, but in this case, the full volume of storage air on thelocomotive is directly connected and has an unobstructed flow to thebrake pipe, which tends to result in the overcharging of the brakesystem including the auxiliary reservolrs.

Furthermore, with no feed valve device between the reservoir volume andthe brake pipe, no excess pressure will be available for insuring theprompt release of the brakes and the recharging of the brake system, itbeing necessary to depend entirely upon the operation of the compressorto provide the excess pressure for this purpose, which in many'casesrequires considerable time and even then does not provide the volume ofair necessary to effect the releaseof the brakes and the recharge of thebrake system with the desired facility.

It may also be noted that .with no feed valve device between the storagereservoir and the brake system, there is no provision of a body of airremaining stationary long enough to permit cooling and prec1p1tation ofmoisture as would be the case where the connection between thereservoirs and the brake system is interrupted.

Iuorder to accomplish the objects my invention as above enumerated, Iutilize the two main reservoirs of the standard loco-- 1 and 2 areprovided on the locomotive, the reservoir 1 being connected to the pumpor compressor (not shown) and having a pipe connection 3, containing afeed valve device 4 of the usual construction, and through which fluidunder pressure is supplied to the main reservoir 2. The main reservoir 2is connected by pipe 5 with the valve chamber 6 of the brake valvedevice 7 comprising the usual casing with the rotary slide valve 8contained in valve chamber 6 and adapted to be operated by the handle 9.The usual brake pipe 10 is connected to a port 11 leading to the. seatof the valve 8.

In operation, the main reservoir 1 is charged with fluid under pressureby operation of the usual compressor, and fluid flows through pipe 3 andthe feed valve device 4, charging the main reservoir 2 at a reducedpressure normally carried in the brake'system and according to theadjustment of the feed valve device.

To release the brakes after the brakes have been applied, the brakevalve handle 9 is turned to release position, as shown in the drawing,in which a port 12, through the rotary valve 8, connects the valvechamber 6 with the brake pipe port 11. Fluid under pressure is thensupplied through an unobstructed passage of large capacity directly fromthe reservoir 2 to the brake pipe 10 at such a rate as to ensure-theprompt movement of the triple valve devices throughout the train torelease position and in su-flicient volume to provide for the promptrechar e of the auxiliary reservoirs. The bra e valve handle is thenleft in the release position without the necessity of moving the handleto a running position, and should leakage occur from the brake pipe thepres sure in the brake pipe will be adequatel maintained to prevent thepossible reapplr cation of one or more brakes in the train by areduction in brake pipe pressure at a greater rate than fluid can flowfrom the auxiliary reservoir through the usual feed roove around thetriple valve piston to the %rake ipe.

At tie same time, the reservoir 1 holds in storage a large volume of airat a high pressure which facilitates cooling and the precipitation ofmoisture.

Having now described my invention, what I claim as new and desire tosecure .by Letters Patent, is

1. In a locomotive brake equipment,the combination with a primaryreservoir adapted to be charged with fluid under pressure, a secondaryreservoir, and a reducing valve device through which fluid underpressure is supplied at a reduced pressure from the primary reservoir tothe secondary reservoir, of a brake pipe and a brake valve devicehaving. only one position in which fluid underpressure can be suppliedto the brake pipe, said supply being only from said secondary reservoir.

2. In a locomotive brake, the combination with a reservoir charged onlyat the pressure of fluid normally carried in the brake system, .of'abrake pipe and a. brake valve Y device having only one position in whichfluid under pressure can be supplied to the brake pipe, said supply offluid to the brake pipe being only from said reservoir.

3; The combination with a brake pipe, of a. reservoir charged only at'apressure not exceeding the pressure normally carried in the brake pipe,a brake valve device having a; valve chamber connected at'all times to.

said reservoir and a manually operable valve in said chamber having aposition in which fluid under pressure is supplied from said valvechamber to said brake pipe.

4. The combination with a. brake pipe, of

SIDNEY G. DOWN.

